This invention relates to a combination of a reversible plough and a seed preparation device, such combination being intended to be drawn behind a tractor or other propelling vehicle and to carry out in a single pass a ploughing and seed preparation action to make the soil ready for subsequent seed drilling.
A combination of a plough and a seed preparation device, such as a packer, is known, and the combination has the advantage of enabling the ground (which usually will comprise untilled ground such as straw stubble) to be both ploughed and then prepared ready for seeding in a single operation. This reduces the labor, time, and cost of preparing the ground and also total tractor time, as compared with previous practice of first ploughing the ground and then following with preparation of the ploughed surface in a separate and subsequent operation.
However, many existing combinations are relatively simple and merely comprise a temporary hitching together with a seed preparation device, such as a packer, to the rear of a trailed plough, so that the packer follows the plough rather in the manner in which a trailer follows a tractor. This means that the hitching together is a simple type of pivot hitch, which has to be uncoupled at the end of each series of ploughed furrows before the tractor and plough turn in the headland, the plough bodies are reversed, and then the packer is re-coupled to the rear of the plough frame for a return pass along the field.
In this simple and relatively unsophisticated existing design, the packer usually has two separate hitching points, one of which is coupled to the rear of the plough frame for travel in one direction, and the other is coupled to the rear of the plough frame for travel in the return direction. The packer, therefore, has to have one of its two hitches uncoupled just short of the headland each time. And the packer then remains parked in this position, while the tractor and plough turn round and the plough bodies are reversed, before the hitching point at the rear of the plough frame can be brought into register with the other of the hitches on the packer. This is an inconvenient and a time consuming task, which has to be carried out each time the combination reaches each headland. It would be a clear technical advantage if a design of combination could be developed which enables the two trailed components (plough and seed preparation device) to remain coupled together during movement of the combination over the headland.
With a view to avoid the necessity to uncouple the seed preparation device each time, there have been proposed tractor/implement combinations in which the plough is coupled directly behind a tractor in a usual way. But the seed preparation device, e.g. a power harrow, is front mounted on the tractor and comprises two separate implements, one extending perpendicularly to one side of the tractor and the other to the other side. During ploughing in one direction, only one of these implements operates to prepare soil ploughed during a previous passage in a reverse direction. And then after turning round in the headland and reversing the plough bodies, the other of the implements is operated to prepare the soil which has just been ploughed.
This tractor/implement combination is a very unwieldy combination with high inertia which is not easy to handle and maneuver, bearing in mind that the two implements extending laterally of the tractor increase the overall width of the tractor/plough/implement combination to about three times the normal width of the tractor/plough combination.